U.S. Pat. No. 4,414,154 refers to compounds of the formula ##STR2##
The compounds are said to be useful as anticonvulsants, anxiolytics and antidepressants. The foregoing compounds do not have a thiophene ring as part of the tricyclic ring system.
U.S. Pat. No. 4,252,810 refers to compounds of the formula ##STR3## The compounds are said to be useful as antianxiety agents and as muscle relaxants. The compounds of the '810 patent have a different orientation of the thiophene ring than the compounds of the present invention as well as a cyclohepta-rather than a cycloocta-ring as part of the bridged tricyclic ring system.